What are the Optimum Biomechanics of a Basketball Jump Shot?

Introduction

This blog will analyze what the optimum biomechanics of a basketball jump shot are. In basketball, the jump shot is one of the most commonly used shots. It is defined as a shot where the ball is released after a jump. To answer my question I will use biomechanical explanations detailing the optimum technique in a jump shot.  The answers that will help break down how to accurately perform a jump shot are under 4 sub headings, the preoperational stance, power production, levers and release.

Preoperational Stance

Centre of Mass

Stance prior to jumping is important as it allows a player to maintain the desired vertical jump. At the beginning of the stance, players should be on the balls of their feet with their centre of gravity low so the body is evenly distributed (Huston & Grau, 2003).  It is important for a shooter to have feet shoulder width apart so their centre of mass remains along the midline of their body (Struzik, Pietraszewski & Zawadzki, 2014). When force is applied to jump, centre of mass must remain central. This will decrease whole body rotation and an unbalanced landing (Struzik, Pietraszewski & Zawadzki, 2014). If their centre of mass is leaning one way, the shooter will jump in that direction which will reduce their vertical jump and decrease shooting accuracy (Struzik, Pietraszewski & Zawadzki, 2014). Research produced by Huston & Grau (2003) show that accurate shooters sustain a vertical motion while shooting. This motion allows the shooter to be more balanced and help keep their eyes on the basketball ring.

Image 1: Centre of mass along the midline of the body

Image 1 shows how important it is to keep centre of mass along the midline of the body. It also symbolizes Newton’s third law, which will be discussed in detail below. The red arrow represents the force being applied to the ground by the legs (action) and the green arrow represents the vertical force created (reaction).

Power Production

Newton’s Third Law

Newton’s third law stats that “for every action, there is an equal and opposite reaction” (Blazevich, 2010, p. 43). This law is connected to the stance and vertical jump in the preoperational stage. When a player jumps vertically, force from their legs (action) is applied to the ground. This action then forces them up in a vertical direction (reaction). Newton’s third law can also help a player understand and reduce injuries. Struzik, Pietraszewski & Zawadzki (2014) explain how learning a soft landing technique can help reduce inuries.  Even with the assistance of modern cushioned footwear, hard landing causes unnecessary overload on lower limbs, which can lead to an injury. Landing with knees bent can assist with absorbing ground force (Struzik, Pietraszewski & Zawadzki, 2014).

Impulse Momentum

In a game situation it is likely that a player will be moving before they shoot. Therefore, a player’s momentum needs to be changed into a vertical jump. Blazevich (2010, p. 51) states that the greater and longer the force is applied, the greater the change in momentum. This is known as impulse momentum (Blazevich, 2010, p. 51.). A basketballer attempting a jump shot needs to understand that in order to accurately shoot a basketball, forward momentum must be transferred into their vertical jump without exerting too much momentum onto the ball (Struzik, Pietraszewski & Zawadzki, 2014). The quicker a player generates force from their lower limbs into their vertical jump, the quicker they will be able to shoot (Struzik, Pietraszewski & Zawadzki, 2014). An early shot will give them a competitive advantage against their opponent who will try to block their shot.

Summation of Forces

For a shooter to produce efficient power on their shot they must use what is known as a summation of forces beginning with their lower limbs and then into their upper body (Blazevich, 2010, p. 68). As force increases from each muscle group, the player is able generate greater shot power. If a player only uses power generated from their arms, wrists and fingers, shooting distance will be significantly decreased and less effiecient (Struzik, Pietraszewski & Zawadzki, 2014).

Image 2: Summation of Forces

Summation of forces is illustrated in image 2. Force from the calves and quads push down onto the ground, creating an equal and opposite reaction. This force is then transferred through the trunk, shoulders, biceps, triceps, wrists and finally into the fingers and ball (Struzik, Pietraszewski & Zawadzki, 2014).

Release

Levers

Once force is generated by the lower limbs, force is then transferred into the arms. Wuest & Butcher (2009, p. 237) explain how levers give an advantage by creating speed, strength and range of motion. Correct technique can optimize the shot power generated by the arms (lever) allowing for greater shot distance and accuracy. Wuest & Butcher (2009, p. 237) describe levers to have 3 important aspects, a fulcrum, a force arm and a resistance arm. Within the body there are first class, second class and third class levers; however, in the jump shot 2 third class levers are utilized (Wuest & Butcher, 2009, p. 237)

Image 3: Power generated from a third class lever

Image 3 shows power gained from the triceps muscle as it moves from a concentric contraction into an eccentric contraction. The forearm (force) connects to the triceps via the elbow joint (fulcrum). Generating power starting with the triceps and into the forearm allows a player to shoot from longer distances.

Optimizing technique in the next third class lever allows a player greater accuracy on their shot. The fulcrum of this lever is located in the wrist and the forearm generates the force. Image 4 shows how this lever helps a player direct the ball with greater accuracy using their fingertips.

Image 4: Power generated from a second third class lever

Projection Angle

Studies done by Miller & Bartlett (1996) show that the optimum angle of release for shots ranging between 2.5m and 5m is between 52° and 55°. Longer shots utilized release angles between 48° and 50°. The angle of release of a basketball is also directly related to its entry angle (Okazaki & Rodacki, 2012). When the entry angle is decreased, the target size also decreases, which can be seen in Image 5 shown by T. Optimum angle of release depends on the distance away from the basket and height of the jump.

Image 5: Optimum Entry Angle

Follow Through

The Magnus Effect

A basketballs flight path can be affected by spin. Blazevich (2010, p. 179) explains that a spinning ball ‘grabs’ air flowing past it because of friction between the ball and the air. These particles and other air particles that touch create the ball to spin. Air speed on one side of a ball is less (high pressure) than air speed on the other side (low pressure) creating what is known as a pressure differential (Blazevich, 2010, p. 180).  A basketballer who directs their shot towards the ring but drags or pulls their fingertips underneath the ball slightly will create backspin.

How does backspin improve accuracy?

Applying backspin on a basketball softens the shot and allows it to rebound into the basket if it does not cleanly pass through the ring (Huston & Grau, 2003). A basketball with no backspin will hit the backboard or ring flat causing it to spring off in any direction. Research conducted by Huston & Grau (2003) shows how if a basketball hits the rim or backboard, backspin decreases the horizontal velocity of a basketball allowing it deflect in a downward direction and into the ring.

How else can we use this information?

The major question of this blog was around analyzing what the optimum biomechanical principals were used in a jump shot. Some of the above principals examined can be applied to other sports.

All sports require excellent alignment and positioning of an athletes centre of mass and centre of gravity. The preoperational stance detailed in this blog can be transfer into a netball shot. Newton’s third law can also help coaches and athletes understand the forces behind certain skills. For example, a tennis serve requires the player to use power from their lower legs (action), pushing them up in a vertical direction (reaction).

Athletes performing in the high jump can use the force production information by measuring how much force their legs can produce. They will understand that training their legs will increase power and improve their vertical jump. An athlete competing in shot put can use this information in regards to summation of forces. Force can be maximized starting with their legs and into their arms.

  

Levers are also beneficial to basketballers and other athletes who may have read this blog. The answer above concludes that the jump shot uses two different levers, which both help in gaining power, and accuracy. This information could be applied to other sports by isolating where levers are used for a particular skill, and then working to increase the strength of the muscles that provide the effort for that lever.

Understanding projection angle can help a variety of athletes that are trying to master the trajectory of an object. An athlete competing in javelin needs to understand the importance of their angle of release in order to increase their distance of their throw. Similarly, a netball player rerading this blod will understand that they need to shoot at the optimum angle so that they have a bigger target to hit.

Learning the technique behind the backspin of a basketball can be transferred into netball shots. The application is identical and can assist netball players score a similar goal.

Lastly Blazevich (2012, p. 210) explains that an athlete wanting to perform a skill can create a step-by-step plan similar to the blog above. According to Blazevich (2012, p. 211) “a detailed plan can be important in order to correct noticeable biomechanical flaws.”

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References

Huston, R. & Grau, C. (2003). Basketball shooting strategies—the free throw, direct shot and layup. Sports Engineering, 6(1), 49-64.

Miller, S., & Bartlett, R. (1996). The relationship between basketball shooting kinematics, distance and playing position. Journal of sports sciences, 14(3), 243-253.

Okazaki, A., & Rodacki, F. (2012). Increased distance of shooting on basketball jump shot. Journal of sports science & medicine, 11(2), 231.

Struzik, A., Pietraszewski, B., & Zawadzki, J. (2014). Biomechanical Analysis of the Jump Shot in Basketball. Journal of human kinetics, 42(1), 73-79.

Wuest, D. & Bucher, C. (2009). Foundations of physical education, exercise science, and sport. McGraw-Hill Higher Education.